Comparison of the methyl ester ofL-tyrosine hydrochloride and its methanol monosolvate

Abstract

Solvent-free (2S)-methyl 2-ammonio-3-(4-hydroxyphenyl)propionate chloride, C10H14NO3+.Cl-, (I), and its methanol solvate, C10H14NO3+.Cl-.CH3OH, (II), are obtained from different solvents: crystallization from ethanol or propan-2-ol gives the same solvent-free crystals of (I) in both cases, while crystals of (II) were obtained by crystallization from methanol. The structure of (I) is characterized by the presence of two-dimensional layers linked together by N-H...Cl and O-H...Cl hydrogen bonds and also by C-H...O contacts. Incorporation of the methanol solvent molecule in (II) introduces additional O-H...O hydrogen bonds linking the two-dimensional layers, resulting in the formation of a three-dimensional network.

L-Serine methyl ester hydrochloride

“…Esterification of the carboxyl group of amino acids plays an important role in the synthesis of peptides, especially due to the increased solubility in non-aquous organic solvents, see: Bodanszky (1993). For related structures, see: Bryndal et al (2006); Gö rbitz (1989). For the determination of the absolute structure, see: Flack & Bernardinelli (2000); Flack & Shmueli (2007); Hooft et al (2008).…”

Tyrosine alkyl esters as prodrug: the structure and intermolecular interactions of l-tyrosine methyl ester compared to l-tyrosine and its ethyl and n-butyl esters

“…Eventually, also the structure of D-Tyr was deposited in the Cambridge Structural Database [24,25]. Tyrosine alkyl esters received less attention, but the crystal structures for a number of them and some salts have been determined: D-tyrosine ethyl ester (D-TEE) [26], L-tyrosine n-butyl ester (n-butyl (S)-2-amino-3-(4-hydroxyphenyl)propionate) (L-TBE) [27], L-tyrosine methyl ester hydrochloride (L-TMEÁHCl), and one of its solvates (L-TMEÁHClÁCH 3 OH) [28].…”

“…Despite the fact that L-TME is commercially available, no crystal structure exists in literature except for those of the above mentioned salts [28]. As part of the aging study, the crystal structure of L-TME was obtained by singlecrystal X-ray diffraction.…”

Valyl benzyl ester chloride

“…For valsartan, see: Black et al (1997); Buhlmayer et al (1994). For related structures, see: Bryndal et al (2006); Jaeger et al (2003); Nastopoulos et al (1987). For a description of the Cambridge Structural Database, see: Allen (2002).…”

“…In the Cambridge Structural Database (Allen, 2002), there are 25 organic structures of the amino acid ester halides, and 10 of them display similar crystal packing and appropriate unit-cell parameter. For instance, L-tyrosyl methyl ester chloride (Bryndal et al, 2006) crystallizes in P2 1 2 1 2 1 space group with one of the unit-cell parameters 5.424 (2) Å, valyl methyl ester chloride (Jaeger et al, 2003) -also P2 1 2 1 2 1 , with 5.894 (2) Å, and (S-benzyl-L-cysteine methyl ester hydrochloride (Nastopoulos et al, 1987) -in P2 1 with c = 5.211 (2) Å.…”